docs: def set_range(self, range):
          """Set the range of the instrument.
  
          A range is a tuple of two Notes or note strings.
          """
          if type(range[0]) == str:
              range[0] = Note(range[0])
              range[1] = Note(range[1])
          if not hasattr(range[0], 'name'):
              raise UnexpectedObjectError("Unexpected object '%s'. "
                      "Expecting a mingus.containers.Note object" % range[0])
          self.range = range